#include<stdio.h>
#include<math.h>

int isTriangle(int a, int b, int c);

int main()
{
    int a, b, c;
    double area, perimeter;
    scanf("%d %d %d", &a, &b, &c);

    if (isTriangle(a, b, c))
    {
        perimeter = a + b + c;
        double s = perimeter / 2;
        area = sqrt(s * (s - a) * (s - b) * (s - c));
        printf("area = %.2f; perimeter = %.2f\n", area, perimeter);
    }
    else
    {
        printf("These sides do not correspond to a valid triangle\n");
    }

    return 0;
}

int isTriangle(int a, int b, int c)
{
	if(a + b > c && a + c > b && b + c > a)
	{
		return 1;
	}
	else
	{
		return 0;
	}
}

